419 research outputs found
Hidden-Markov Program Algebra with iteration
We use Hidden Markov Models to motivate a quantitative compositional
semantics for noninterference-based security with iteration, including a
refinement- or "implements" relation that compares two programs with respect to
their information leakage; and we propose a program algebra for source-level
reasoning about such programs, in particular as a means of establishing that an
"implementation" program leaks no more than its "specification" program.
This joins two themes: we extend our earlier work, having iteration but only
qualitative, by making it quantitative; and we extend our earlier quantitative
work by including iteration. We advocate stepwise refinement and
source-level program algebra, both as conceptual reasoning tools and as targets
for automated assistance. A selection of algebraic laws is given to support
this view in the case of quantitative noninterference; and it is demonstrated
on a simple iterated password-guessing attack
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Pulmonary Artery Dissection Post-blunt Thoracoabdominal Trauma
Background: Pulmonary artery dissection is a rare condition that is usually diagnosed in patients exhibiting chronic pulmonary arterial hypertension, congenital heart abnormalities or secondary to iatrogenic injury. Diagnosis is often made at autopsy as many patients experience sudden death when the pulmonary artery dissection progresses rapidly and ruptures into the pericardium, resulting in acute cardiac tamponade.Case Presentation: We report a case of pulmonary artery dissection, which resulted from blunt thoracic trauma diagnosed in the emergency department
FACS-sorted putative oogonial stem cells from the ovary are neither DDX4-positive nor germ cells
Whether the adult mammalian ovary contains oogonial stem cells (OSCs) is controversial. They have been isolated by a live-cell sorting method using the germ cell marker DDX4, which has previously been assumed to be cytoplasmic, not surfacebound. Furthermore their stem cell and germ cell characteristics remain disputed. Here we show that although OSC-like cells can be isolated from the ovary using an antibody to DDX4, there is no good in silico modelling to support the existence of a surfacebound DDX4. Furthermore these cells when isolated were not expressing DDX4, and did not initially possess germline identity. Despite these unremarkable beginnings, they acquired some pre-meiotic markers in culture, including DDX4, but critically never expressed oocyte-specific markers, and furthermore were not immortal but died after a few months. Our results suggest that freshly isolated OSCs are not germ stem cells, and are not being isolated by their DDX4 expression. However it may be that culture induces some pre-meiotic markers. In summary the present study offers weight to the dogma that the adult ovary is populated by a fixed number of oocytes and that adult de novo production is a rare or insignificant event
“Blurred boundaries”: When nurses and midwives give anti-vaccination advice on Facebook
© The Author(s) 2022. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1177/09697330211041749Background: Nurses and midwives have a professional obligation to promote health and prevent disease, and therefore they have an essential role to play in vaccination. Despite this, some nurses and midwives have been found to take an anti-vaccination stance and promulgate misinformation about vaccines, often using Facebook as a platform to do so. Research question: This article reports on one component and dataset from a larger study – ‘the positives, perils and pitfalls of Facebook for nurses’. It explores the specific issue of nurses and midwives who take an anti-vaccination stance, deemed to be unprofessional by crossing professional boundaries and by providing medical information on Facebook that is not within their scope of practice. Participants: Data were collected via an online worldwide survey from nurse and midwife participants, distributed and ‘snowballed’ through relevant nursing and midwifery groups on Facebook. In total, 1644 Registered Nurses and Midwives, and Enrolled Nurses worldwide attempted the online survey. There were 1100 (66.9%) completed surveys and 54 partially (33.1%) completed surveys. Semi-structured interviews were also conducted online using Skype® with 17 participants in Australia. Ethical considerations: Ethical processes and procedures have been adhered to relating to privacy, confidentiality and anonymity of the participants. Findings/results: A mixed-methods approach was used, including descriptive and content analysis of the quantitative survey data and thematic analysis of the qualitative interview data. The main theme ‘blurred boundaries’ was generated, which comprised three sub-themes: ‘follow the science, ‘abuse of power and erosion of trust’ and ‘the moral and ethical responsibility to safeguard public health’. The results offer an important and unique understanding of how nurses and midwives interpret the conduct of fellow health professionals as unprofessional and crossing the professional boundary if they used Facebook to promulgate anti-vaccination messages and/or give medical advice online. Conclusion: There are many positives and negatives for nurses and midwives associated with using Facebook for personal and professional communication, which is in keeping with the results of the larger study from which this article is taken. Professional behaviour is a key theme in the larger research as is the ethical construct of ‘every act has a consequence’; however, in this article, the theme ‘blurred boundaries’ offers an overall understanding of how nurses and midwives interpret the behaviour of their colleagues who espouse anti-vaccination sentiment and/or give medical advice online that is outside their scope of practice and education.Peer reviewe
Modeling the Potential Distribution of Bacillus anthracis under Multiple Climate Change Scenarios for Kazakhstan
Anthrax, caused by the bacterium Bacillus anthracis, is a zoonotic disease that persists throughout much of the world in livestock, wildlife, and secondarily infects humans. This is true across much of Central Asia, and particularly the Steppe region, including Kazakhstan. This study employed the Genetic Algorithm for Rule-set Prediction (GARP) to model the current and future geographic distribution of Bacillus anthracis in Kazakhstan based on the A2 and B2 IPCC SRES climate change scenarios using a 5-variable data set at 55 km2 and 8 km2 and a 6-variable BioClim data set at 8 km2. Future models suggest large areas predicted under current conditions may be reduced by 2050 with the A2 model predicting ∼14–16% loss across the three spatial resolutions. There was greater variability in the B2 models across scenarios predicting ∼15% loss at 55 km2, ∼34% loss at 8 km2, and ∼30% loss with the BioClim variables. Only very small areas of habitat expansion into new areas were predicted by either A2 or B2 in any models. Greater areas of habitat loss are predicted in the southern regions of Kazakhstan by A2 and B2 models, while moderate habitat loss is also predicted in the northern regions by either B2 model at 8 km2. Anthrax disease control relies mainly on livestock vaccination and proper carcass disposal, both of which require adequate surveillance. In many situations, including that of Kazakhstan, vaccine resources are limited, and understanding the geographic distribution of the organism, in tandem with current data on livestock population dynamics, can aid in properly allocating doses. While speculative, contemplating future changes in livestock distributions and B. anthracis spore promoting environments can be useful for establishing future surveillance priorities. This study may also have broader applications to global public health surveillance relating to other diseases in addition to B. anthracis
An analysis of appropriate delivery of postoperative radiation therapy for endometrial cancer using the RAND/UCLA Appropriateness Method: Executive summary
PurposeTo summarize the results of American Society for Radiation Oncology (ASTRO)'s analysis of appropriate delivery of postoperative radiation therapy (RT) for endometrial cancer using the RAND/University of California, Los Angeles (UCLA) Appropriateness Method, outline areas of convergence and divergence with the 2014 ASTRO endometrial Guideline, and highlight where this analysis provides new information or perspective.Methods and materialsThe RAND/UCLA Appropriateness Method was used to combine available evidence with expert opinion. A comprehensive literature review was conducted and a multidisciplinary panel rated the appropriateness of RT options for different clinical scenarios. Treatments were categorized by the median rating as Appropriate, Uncertain, or Inappropriate.ResultsThe ASTRO endometrial Guideline and this analysis using the RAND/UCLA Appropriateness Method did not recommend adjuvant RT for early-stage, low-risk endometrioid cancers and largely agree regarding use of vaginal brachytherapy for low-intermediate and high-intermediate risk patients. For more advanced endometrioid cancer, chemotherapy with RT is supported by both documents. The Guideline and the RAND/UCLA analysis diverged regarding use of pelvic radiation. For stages II and III, this analysis rated external beam RT plus vaginal brachytherapy Appropriate, whereas the Guideline preferred external beam alone. In addition, this analysis offers insight on the role of histology, extent of nodal dissection, and para-aortic nodal irradiation; the use of intensity modulated RT; and management of stage IVA.ConclusionsThis analysis based on the RAND/UCLA Method shows significant agreement with the 2014 endometrial Guideline. Areas of divergence, often in scenarios with low-level evidence, included use of external beam RT plus vaginal brachytherapy in stages II and III and external beam RT alone in early-stage patients. Furthermore, the analysis explores other important questions regarding management of this disease site
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